package com.ruoyi.activiti.service.impl;

import org.activiti.engine.*;
import org.activiti.engine.history.HistoricActivityInstance;
import org.activiti.engine.impl.RepositoryServiceImpl;
import org.activiti.engine.impl.persistence.entity.ProcessDefinitionEntity;
import org.activiti.engine.impl.persistence.entity.TaskEntity;
import org.activiti.engine.impl.pvm.PvmTransition;
import org.activiti.engine.impl.pvm.process.ActivityImpl;
import org.activiti.engine.impl.pvm.process.ProcessDefinitionImpl;
import org.activiti.engine.impl.pvm.process.TransitionImpl;
import org.activiti.engine.runtime.ProcessInstance;
import org.activiti.engine.task.Task;
import org.apache.commons.lang3.StringUtils;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * 流程操作核心类<br>
 * <p>
 * 此核心类主要处理：流程通过、驳回、转办、中止、挂起等核心操作<br>
 */

public class ProcessCustomService {

    @Resource
    private static RepositoryService repositoryService;
    @Resource
    private static RuntimeService runtimeService;
    @Resource
    private static TaskService taskService;
    @Resource
    private static FormService formService;
    @Resource
    private static HistoryService historyService;
    /**
     * 退回流程
     *
     * @param taskId     当前任务ID
     * @param activityId 退回节点ID
     * @param variables  流程存储参数
     * @throws Exception
     */

    public static void backProcess(String taskId, String activityId,
                                   Map<String, Object> variables) throws Exception {
        if (StringUtils.isEmpty(activityId)) {
            throw new Exception("退回目标节点ID为空！");
        }
        // 查找所有并行任务节点，同时驳回
        List<Task> taskList = findTaskListByKey(findProcessInstanceByTaskId(
                taskId).getId(), findTaskById(taskId).getTaskDefinitionKey());
        for (Task task : taskList) {
            commitProcess(task.getId(), variables, activityId);
        }

    }


    /**
     * 取回流程
     *
     * @param taskId     当前任务ID
     * @param activityId 取回节点ID
     * @throws Exception
     */

    public static void callBackProcess(String taskId, String activityId)

            throws Exception {

        if (StringUtils.isEmpty(activityId)) {
            throw new Exception("退回目标节点ID为空！");
        }
        // 查找所有并行任务节点，同时取回
        List<Task> taskList = findTaskListByKey(findProcessInstanceByTaskId(

                taskId).getId(), findTaskById(taskId).getTaskDefinitionKey());
        for (Task task : taskList) {
            commitProcess(task.getId(), null, activityId);
        }

    }


    /**
     * 清空指定活动节点流向
     *
     * @param activityImpl 活动节点
     * @return 节点流向集合
     */

    private static List<PvmTransition> clearTransition(ActivityImpl activityImpl) {

        // 存储当前节点所有流向临时变量

        List<PvmTransition> oriPvmTransitionList = new ArrayList<PvmTransition>();

        // 获取当前节点所有流向，存储到临时变量，然后清空

        List<PvmTransition> pvmTransitionList = activityImpl

                .getOutgoingTransitions();

        for (PvmTransition pvmTransition : pvmTransitionList) {

            oriPvmTransitionList.add(pvmTransition);

        }

        pvmTransitionList.clear();


        return oriPvmTransitionList;

    }


    /**
     * @param taskId     当前任务ID
     * @param variables  流程变量
     * @param activityId 流程转向执行任务节点ID<br>
     *                   <p>
     *                   此参数为空，默认为提交操作
     * @throws Exception
     */

    private static void commitProcess(String taskId, Map<String, Object> variables,

                                      String activityId) throws Exception {

        if (variables == null) {
            variables = new HashMap<String, Object>();
        }
        // 跳转节点为空，默认提交操作
        if (StringUtils.isEmpty(activityId)) {
            taskService.complete(taskId, variables);
        } else {// 流程转向操作
            turnTransition(taskId, activityId, variables);
        }

    }


    /**
     * 中止流程(特权人直接审批通过等)
     *
     * @param taskId
     */

    public static void endProcess(String taskId) throws Exception {
        ActivityImpl endActivity = findActivitiImpl(taskId, "end");
        commitProcess(taskId, null, endActivity.getId());

    }


    /**
     * 根据流入任务集合，查询最近一次的流入任务节点
     *
     * @param processInstance 流程实例
     * @param tempList        流入任务集合
     * @return
     */

    private static ActivityImpl filterNewestActivity(ProcessInstance processInstance,
                                                     List<ActivityImpl> tempList) {
        while (tempList.size() > 0) {
            ActivityImpl activity_1 = tempList.get(0);
            HistoricActivityInstance activityInstance_1 = findHistoricUserTask(
                    processInstance, activity_1.getId());
            if (activityInstance_1 == null) {
                tempList.remove(activity_1);
                continue;
            }
            if (tempList.size() > 1) {
                ActivityImpl activity_2 = tempList.get(1);

                HistoricActivityInstance activityInstance_2 = findHistoricUserTask(

                        processInstance, activity_2.getId());

                if (activityInstance_2 == null) {

                    tempList.remove(activity_2);

                    continue;

                }


                if (activityInstance_1.getEndTime().before(

                        activityInstance_2.getEndTime())) {

                    tempList.remove(activity_1);

                } else {

                    tempList.remove(activity_2);

                }

            } else {

                break;

            }

        }

        if (tempList.size() > 0) {

            return tempList.get(0);

        }

        return null;

    }


    /**
     * 根据任务ID和节点ID获取活动节点 <br>
     *
     * @param taskId     任务ID
     * @param activityId 活动节点ID <br>
     *                   <p>
     *                   如果为null或""，则默认查询当前活动节点 <br>
     *                   <p>
     *                   如果为"end"，则查询结束节点 <br>
     * @return
     * @throws Exception
     */

    private static ActivityImpl findActivitiImpl(String taskId, String activityId)

            throws Exception {

        // 取得流程定义

        ProcessDefinitionEntity processDefinition = findProcessDefinitionEntityByTaskId(taskId);


        // 获取当前活动节点ID

        if (StringUtils.isEmpty(activityId)) {

            activityId = findTaskById(taskId).getTaskDefinitionKey();

        }


        // 根据流程定义，获取该流程实例的结束节点

        if (activityId.toUpperCase().equals("END")) {

            for (ActivityImpl activityImpl : processDefinition.getActivities()) {

                List<PvmTransition> pvmTransitionList = activityImpl

                        .getOutgoingTransitions();

                if (pvmTransitionList.isEmpty()) {

                    return activityImpl;

                }

            }

        }


        // 根据节点ID，获取对应的活动节点

        ActivityImpl activityImpl = ((ProcessDefinitionImpl) processDefinition)

                .findActivity(activityId);


        return activityImpl;

    }


    /**
     * 根据当前任务ID，查询可以驳回的任务节点
     *
     * @param taskId 当前任务ID
     */

    public static List<ActivityImpl> findBackAvtivity(String taskId) throws Exception {

        List<ActivityImpl> rtnList = iteratorBackActivity(taskId, findActivitiImpl(taskId,

                null), new ArrayList<ActivityImpl>(),

                new ArrayList<ActivityImpl>());

        return reverList(rtnList);

    }


    /**
     * 查询指定任务节点的最新记录
     *
     * @param processInstance 流程实例
     * @param activityId
     * @return
     */

    private static HistoricActivityInstance findHistoricUserTask(

            ProcessInstance processInstance, String activityId) {

        HistoricActivityInstance rtnVal = null;

        // 查询当前流程实例审批结束的历史节点

        List<HistoricActivityInstance> historicActivityInstances = historyService

                .createHistoricActivityInstanceQuery().activityType("userTask")

                .processInstanceId(processInstance.getId()).activityId(

                        activityId).finished()

                .orderByHistoricActivityInstanceEndTime().desc().list();

        if (historicActivityInstances.size() > 0) {

            rtnVal = historicActivityInstances.get(0);

        }


        return rtnVal;

    }


    /**
     * 根据当前节点，查询输出流向是否为并行终点，如果为并行终点，则拼装对应的并行起点ID
     *
     * @param activityImpl 当前节点
     * @return
     */

    private static String findParallelGatewayId(ActivityImpl activityImpl) {

        List<PvmTransition> incomingTransitions = activityImpl

                .getOutgoingTransitions();

        for (PvmTransition pvmTransition : incomingTransitions) {

            TransitionImpl transitionImpl = (TransitionImpl) pvmTransition;

            activityImpl = transitionImpl.getDestination();

            String type = (String) activityImpl.getProperty("type");

            if ("parallelGateway".equals(type)) {// 并行路线

                String gatewayId = activityImpl.getId();

                String gatewayType = gatewayId.substring(gatewayId

                        .lastIndexOf("_") + 1);

                if ("END".equals(gatewayType.toUpperCase())) {

                    return gatewayId.substring(0, gatewayId.lastIndexOf("_"))

                            + "_start";

                }

            }

        }

        return null;

    }


    /**
     * 根据任务ID获取流程定义
     *
     * @param taskId 任务ID
     * @return
     * @throws Exception
     */

    public static ProcessDefinitionEntity findProcessDefinitionEntityByTaskId(

            String taskId) throws Exception {

        // 取得流程定义

        ProcessDefinitionEntity processDefinition = (ProcessDefinitionEntity) ((RepositoryServiceImpl) repositoryService)

                .getDeployedProcessDefinition(findTaskById(taskId)

                        .getProcessDefinitionId());


        if (processDefinition == null) {

            throw new Exception("流程定义未找到!");

        }


        return processDefinition;

    }


    /**
     * 根据任务ID获取对应的流程实例
     *
     * @param taskId 任务ID
     * @return
     * @throws Exception
     */

    public static ProcessInstance findProcessInstanceByTaskId(String taskId)

            throws Exception {

        // 找到流程实例

        ProcessInstance processInstance = runtimeService

                .createProcessInstanceQuery().processInstanceId(

                        findTaskById(taskId).getProcessInstanceId())

                .singleResult();

        if (processInstance == null) {

            throw new Exception("流程实例未找到!");

        }

        return processInstance;

    }


    /**
     * 根据任务ID获得任务实例
     *
     * @param taskId 任务ID
     * @return
     * @throws Exception
     */

    private static TaskEntity findTaskById(String taskId) throws Exception {

        TaskEntity task = (TaskEntity) taskService.createTaskQuery().taskId(

                taskId).singleResult();

        if (task == null) {

            throw new Exception("任务实例未找到!");

        }

        return task;

    }


    /**
     * 根据流程实例ID和任务key值查询所有同级任务集合
     *
     * @param processInstanceId
     * @param key
     * @return
     */

    private static List<Task> findTaskListByKey(String processInstanceId, String key) {

        return taskService.createTaskQuery().processInstanceId(

                processInstanceId).taskDefinitionKey(key).list();

    }


    /**
     * 迭代循环流程树结构，查询当前节点可驳回的任务节点
     *
     * @param taskId       当前任务ID
     * @param currActivity 当前活动节点
     * @param rtnList      存储回退节点集合
     * @param tempList     临时存储节点集合（存储一次迭代过程中的同级userTask节点）
     * @return 回退节点集合
     */

    private static List<ActivityImpl> iteratorBackActivity(String taskId,

                                                           ActivityImpl currActivity, List<ActivityImpl> rtnList,

                                                           List<ActivityImpl> tempList) throws Exception {

        // 查询流程定义，生成流程树结构

        ProcessInstance processInstance = findProcessInstanceByTaskId(taskId);


        // 当前节点的流入来源

        List<PvmTransition> incomingTransitions = currActivity

                .getIncomingTransitions();

        // 条件分支节点集合，userTask节点遍历完毕，迭代遍历此集合，查询条件分支对应的userTask节点

        List<ActivityImpl> exclusiveGateways = new ArrayList<ActivityImpl>();

        // 并行节点集合，userTask节点遍历完毕，迭代遍历此集合，查询并行节点对应的userTask节点

        List<ActivityImpl> parallelGateways = new ArrayList<ActivityImpl>();

        // 遍历当前节点所有流入路径

        for (PvmTransition pvmTransition : incomingTransitions) {

            TransitionImpl transitionImpl = (TransitionImpl) pvmTransition;

            ActivityImpl activityImpl = transitionImpl.getSource();

            String type = (String) activityImpl.getProperty("type");

            /**
             * 并行节点配置要求：<br>
             * 必须成对出现，且要求分别配置节点ID为:XXX_start(开始)，XXX_end(结束)

             */

            if ("parallelGateway".equals(type)) {// 并行路线

                String gatewayId = activityImpl.getId();

                String gatewayType = gatewayId.substring(gatewayId

                        .lastIndexOf("_") + 1);

                if ("START".equals(gatewayType.toUpperCase())) {// 并行起点，停止递归

                    return rtnList;

                } else {// 并行终点，临时存储此节点，本次循环结束，迭代集合，查询对应的userTask节点

                    parallelGateways.add(activityImpl);

                }

            } else if ("startEvent".equals(type)) {// 开始节点，停止递归

                return rtnList;

            } else if ("userTask".equals(type)) {// 用户任务

                tempList.add(activityImpl);

            } else if ("exclusiveGateway".equals(type)) {// 分支路线，临时存储此节点，本次循环结束，迭代集合，查询对应的userTask节点

                currActivity = transitionImpl.getSource();

                exclusiveGateways.add(currActivity);

            }

        }


        /**
         * 迭代条件分支集合，查询对应的userTask节点

         */

        for (ActivityImpl activityImpl : exclusiveGateways) {

            iteratorBackActivity(taskId, activityImpl, rtnList, tempList);

        }


        /**
         * 迭代并行集合，查询对应的userTask节点

         */

        for (ActivityImpl activityImpl : parallelGateways) {

            iteratorBackActivity(taskId, activityImpl, rtnList, tempList);

        }


        /**
         * 根据同级userTask集合，过滤最近发生的节点

         */

        currActivity = filterNewestActivity(processInstance, tempList);

        if (currActivity != null) {

            // 查询当前节点的流向是否为并行终点，并获取并行起点ID

            String id = findParallelGatewayId(currActivity);

            if (StringUtils.isEmpty(id)) {// 并行起点ID为空，此节点流向不是并行终点，符合驳回条件，存储此节点

                rtnList.add(currActivity);

            } else {// 根据并行起点ID查询当前节点，然后迭代查询其对应的userTask任务节点

                currActivity = findActivitiImpl(taskId, id);

            }


            // 清空本次迭代临时集合

            tempList.clear();

            // 执行下次迭代

            iteratorBackActivity(taskId, currActivity, rtnList, tempList);

        }

        return rtnList;

    }


    /**
     * 还原指定活动节点流向
     *
     * @param activityImpl         活动节点
     * @param oriPvmTransitionList 原有节点流向集合
     */

    private static void restoreTransition(ActivityImpl activityImpl,

                                          List<PvmTransition> oriPvmTransitionList) {

        // 清空现有流向

        List<PvmTransition> pvmTransitionList = activityImpl

                .getOutgoingTransitions();

        pvmTransitionList.clear();

        // 还原以前流向

        for (PvmTransition pvmTransition : oriPvmTransitionList) {

            pvmTransitionList.add(pvmTransition);

        }

    }


    /**
     * 反向排序list集合，便于驳回节点按顺序显示
     *
     * @param list
     * @return
     */

    private static List<ActivityImpl> reverList(List<ActivityImpl> list) {

        List<ActivityImpl> rtnList = new ArrayList<ActivityImpl>();

        // 由于迭代出现重复数据，排除重复

        for (int i = list.size(); i > 0; i--) {

            if (!rtnList.contains(list.get(i - 1)))

                rtnList.add(list.get(i - 1));

        }

        return rtnList;

    }


    /**
     * 转办流程
     *
     * @param taskId   当前任务节点ID
     * @param userCode 被转办人Code
     */

    public static void transferAssignee(String taskId, String userCode) {
        taskService.setAssignee(taskId, userCode);

    }


    /**
     * 流程转向操作
     *
     * @param taskId     当前任务ID
     * @param activityId 目标节点任务ID
     * @param variables  流程变量
     * @throws Exception
     */

    private static void turnTransition(String taskId, String activityId,

                                       Map<String, Object> variables) throws Exception {
        // 当前节点
        ActivityImpl currActivity = findActivitiImpl(taskId, null);
        // 清空当前流向
        List<PvmTransition> oriPvmTransitionList = clearTransition(currActivity);
        // 创建新流向
        TransitionImpl newTransition = currActivity.createOutgoingTransition();
        // 目标节点
        ActivityImpl pointActivity = findActivitiImpl(taskId, activityId);
        // 设置新流向的目标节点
        newTransition.setDestination(pointActivity);
        // 执行转向任务
        taskService.complete(taskId, variables);
        // 删除目标节点新流入
        pointActivity.getIncomingTransitions().remove(newTransition);
        // 还原以前流向
        restoreTransition(currActivity, oriPvmTransitionList);

    }


}
